Two degrees of climate change may be too much

Touring Alaska this week to shine a spotlight on global warming, President Obama warned that “climate change is no longer some far-off problem. It is happening here; it is happening now. Climate change is already disrupting our agriculture and ecosystems, our water and food supplies, our energy, our infrastructure, human health, human safety. Now. Today.”

This wasn’t supposed to happen. In 2009, 114 countries signed the Copenhagen Accord, agreeing “to stabilize greenhouse gas concentration in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system;” “recognizing the scientific view” that the increase in global temperature should be held to no more than 2 degrees Celsius” (3.6 degrees Fahrenheit) above the pre-industrial level; and promising greater “long-term cooperative action to combat climate change.”

Paradoxically, an accord that should have spurred the world to immediate action instead seemed to offer some breathing room. Two degrees was meant to be a ceiling, but repeated references to an internationally agreed-upon “threshold” led many people to believe that nothing really bad could happen below 2 degrees—or worse yet, that the number itself was negotiable. Perhaps the biggest failure of the Copenhagen Accord was its pact for “long-term” action. Forty years ago, climate change was a “long-term” problem. Today it’s an emergency.

Today we’re only about halfway to the 2-degree mark, yet the climate is already haywire. Numbers such as 2 degrees and 350 parts per million (or ppm, which many climate activists have identified as a “safe” level for carbon dioxide in the atmosphere) have become enshrined in the climate debate. Meanwhile, though, civilization’s industrial machinery marches on. We’re already at 400 ppm of carbon dioxide, and it looks like we will blow by 2 degrees, too.

Such numbers may mean little to the general public, but they matter a lot to negotiators who will be at Paris climate change talks in December. Unfortunately, the numbers that these negotiators plan to propose will only be part of non-legally-binding pledges—and they represent only what is achievable without too much difficulty, rather than the drastic austerity measures needed to stabilize emissions. In fact, 2 degrees is not an upper limit that the nations of the world recognize and respect, only a target that negotiators know they will overshoot with their expected pledges. The very idea that the Paris conference is a negotiation is ridiculous. You can’t negotiate with the atmosphere.

In hindsight, though, the idea that even 2 degrees of warming would be tolerable is baffling. Homo sapiens have never lived in a world that hot. In an excellent series of special reports for CNN on what 2 degrees of global warming would mean, John D. Sutter lists some of the expected impacts: a melting Arctic, enormous wildfires, more intense hurricanes, water shortages, reduced crop yields, and animals and plants at risk of extinction. Even if warming can be held to 2 degrees, scientists predict that global sea level will rise by at least 20 feet as a result.

The Climate Vulnerable Forum, a coalition of 20 nations that expect severe global-warming effects, has called the 2-degree goal “inadequate” to protect fundamental human rights. “How can we possibly subscribe to more than double the current warming?” asked Mary Ann Lucille L. Sering, secretary of the Philippines Climate Change Commission.

Although the 2-degree target was endorsed in Copenhagen in 2009, and again in Cancún the following year, the parties also agreed to periodically review the adequacy of the target and to consider strengthening it. The majority of countries that have signed and ratified the United Nations Framework Convention on Climate Change now support a lower target of 1.5 degrees, and a review process reported that the lower limit would be “preferable” but that the science supporting it is “less robust.”

What is feasible? The World Bank has warned that a 1.5-degree rise is “locked in,” and that we’re headed toward a warming of 4 degrees by the end of the century. “Scientists, policy-makers and the public already accept that progress will not be enough to keep global average temperature rise within the 2°C limit,” wrote Oliver Geden, head of the EU Research Division at the German Institute for International and Security Affairs, in a recent Nature commentary. “The negotiations’ goal has become what is politically possible, not what is environmentally desirable.”

If you add up the pledges that have been made so far, and nations keep their promises, the world is in for about 3 degrees of warming by 2100. Limiting the warming to 2 degrees would require rapid emissions reductions over the next few decades, declining to zero net emissions shortly after 2050.

It is still possible to limit global warming to 1.5 degrees by 2100 (after a temporary overshoot), according to a paper published in Nature Climate Change a few months ago. But it would mean becoming carbon neutral even earlier than required for a 2-degree scenario.

There is an alternative to meaningless numbers and endless negotiations: going to war against climate change. If the United States can spend nearly $1.7 trillion on the “war on terror,”surely we can spend at least that much to keep our planet from overheating.

The 2-degree goal was chosen based on what was considered to be a scientific consensus about the most likely scenario for climate change. That is not how national security risks are evaluated. “When we think about keeping our country safe, we always consider the worst case scenarios,” said British Foreign Office Minister Baroness Joyce Anelay in a statement introducing a new climate risk assessment commissioned by her office. “That is what guides our policies on nuclear non-proliferation, counter-terrorism, and conflict prevention. We have to think about climate change the same way.”

In a foreword to the report, Anelay writes: “We must remember that in one way, climate change differs from any other subject of diplomatic negotiation: It is governed by a physical process. A process where the risk increases over time, and will continue to do so until we have entirely dealt with its cause.”

Increased risk is not an abstraction. It is record-setting heat, year after year. It is coastal erosion washing away villages in Alaska. It is massive wildfires raging in the American West. “We have to attack these at the source, which is carbon pollution,” Washington Gov. Jay Inslee told the Northwest News Network after flying over the worst fires in his state’s history. “It is difficult to comprehend a central fact of these fires,” Inslee said, “which is nature bats last.” Unfortunately, there won’t be any extra innings.